Natural Selection?

Question

hey guys im back to bug you all with one more question that has seemed to of stumped me yet again.
Here it is

"Natural selection is an editing mechanism rather than an inventive process"

What the heck does that mean? Now i do know what natural selection is but i dont get the other parts to the quote.

Heres part 2 of my question

Is evolution through adaptation the only possible path for a species? In other words, are all species “guaranteed” to evolve?

Any help? Last question for today i promise! Thanks!

Answer 1

Let's put it this way... if you go shopping and put things in your grocery cart, does it DIRECTLY cause new things to appear in the store? That would be kind of ridiculous.

And that is kind of like natural selection. The key word is SELECT. The process isn't about adding anything in, it's about choosing from existing options.

That is also part of the point of your quote. Something OTHER than natural selection IS adding new stuff in. If it weren't, there would very shortly be no choices to select FROM.

As for things being 'guaranteed' to evolve... I don't know of anyone who would put much stock in that idea. Even though selection and mutation are very commonplace and natural processes, it hardly means that they are entirely predictable and not without an element of randomness.

After all, a wolf chasing a pack of animals will probably catch the slowest and weakest one, but will be just as satisfied with the strongest one if it just happens to stumble over a rock. Likewise, even though we can say for certain that a person exposed to lots of radiation is going to have a lot of genetic damage (mutations, in other words), I don't think anyone could possibly say exactly what in any particular set of DNA is going to be hit. It's just a matter of where the particle happens to zing.

So evolution and adaptation and all that are certain to occur given a long enough time, but that's not the ONLY thing happening!

Answer 2

Regarding your first question, I agree that evolution corrects mistakes rather than "encourage" aleatory combinations of genetic material, that can be catastrophic by an individual or a specie. In the process of making copies of the genetic material, mistakes (mutations) may happen in an aleatory way. Many organisms have mechanisms to correct most of these "misspellings". But sometimes these mechanisms fail to correct the mistakes and mutations emerge. If these mutations seriously compromise the survival of the individual, it will just disappear by natural selection (just as if you were editing a book and eliminating the wrong words or sentences).
Regarding your second question, I don´t think that all species are guaranteed to evolve. If a sudden environmental change happens and the specie is not able to adapt to it, the specie Will disappear. The chances for a specie to survive and evolve depend mainly on two factors: the magnitude of the environmental change and the genetic diversity of the specie. The more diversity is present into an specie, the more chances are that at least some individual will be able to adapt to the new environmental conditions.
Hope it helps.

Answer 3

I'll take a stab at these:
1. According to the sequence of events in Darwin's theory,
only the "fittest" survive. Nature has selected the most fit,
and has deleted or edited out the others.
The organisms going through the process of evolution via
natural selection don't strive or invent ways to survive. Instead
they are at the mercy of changes that have occurred to them
by random mutations. Evolution, in other words, does not have a
predetermined , planned or inventive pathway (That would be
an explanation proposed by Lamarck).
2. There is no guarantee to evolve. Look at the lowly
Amoeba. It has "adapted" well over the eons of time
without much change. It's still happy just being a blob.
By the way, binary fission and other methods of asexual
reproduction does not encourage evolutionary changes.

Oh, go ahead, don't be shy, ask another question today:)

Answer 4

1. The process of weeding out good and bad mutations is essentially natural selection. Natural selection doesn't decide that a creature "needs" longer legs or better eyes and then creates it. That creature needs to develop them on its own (through mutations) and then be able to live better with it.

2. Species are never "guaranteed" to evolve. Take, for instance, a species that is adapted to a particular habitat, and then an invasive species (one that is not originally from that area) comes in. The invasive species may be able to compete better for the resources than the original species. The original species will most likely not be able to keep up with the invasive species, and thus be extinct.

Also, if you think about humans, we constantly alter our environment. So people who would normally die off without producing offspring are able to do so. Thus, we are eliminating natural selection. There are also other factors that contribue to evolution (gene flow, for instance).

Answer 5

Natural selection is an editing mechansim because it works on pre-existing models. DNA gets changed upon mutations. Its not an inventive process because it doesnt work on demand, its not like "i need a pair of wings, so let me grow them out of thin air".
A new structure can only be built upon pre existing structures, randomly, not on demand. After that, whatever its helpful stays in the gene pool, whatever its not dies.
If the species doesnt evolve "on time" then the species would die. In other words, if there is a drastic change in the species' environment quickly enough to leave few or no descendants then the species would end there.

Answer 6

"Natural selection is an editing mechanism rather than an inventive process"
This means that natural selection does not create new individuals, it just chooses which individuals to keep or not.

"are all species “guaranteed” to evolve? "
Any system that has inheritance, variation and selection will evolve - this applies not just to species but to any system at all - for example, I am using these ideas to make evolving computer programs.

___________________
Hope that helps, Adam
My website: http://www.cygnetgames.co.uk